Electrically conductive metal wire has long been coated with insulative polymer and wound in coils for use as magnets, where the operating conditions of the magnets require a thin but reliable insulative coating.
Magnet wire is conventionally made by first producing the bare wire and shaping it to the desired cross-section, and later, in an entirely separate operation, applying a coating to the wire. One reason for performing these operations separately is that the conventional coating process takes much longer than the shaping process.
Conventional magnet wire coating processes are troublesome. For example, in many cases they depend on use of solvents which risk polluting the atmosphere.